<template>
  <div class="xtx-numbox">
    <div class="label">{{ props.label }}</div>
    <div class="numbox">
      <a @click="changeNum(-1)" href="javascript:;">-</a>
      <input type="text" readonly :value="num">
      <a @click="changeNum(1)" href="javascript:;">+</a>
    </div>
  </div>
</template>
<script setup>
import { useVModel } from '@vueuse/core'
import { defineProps, defineEmits } from 'vue'
const props = defineProps({
  label: {
    type: String,
    default: ''
  },
  modelValue: {
    type: Number,
    default: 1
  },
  // -完后不能出现负数
  min: {
    type: Number,
    default: 1
  },
  // +完后的最大值不能超过该sku组合的最大库存
  max: {
    type: Number,
    default: 100
  }
})
const emit = defineEmits(['update:modelValue', 'change'])
// 使用useVmodel函数实现双向数据绑定,num是一个ref声明的响应式数据
const num = useVModel(props, 'modelValue', emit)
// 点击+/-去更改数量
function changeNum(step) {
  let newNum = num.value + step
  // 排除临界点
  if (newNum < props.min) newNum = props.min
  if (newNum > props.max) newNum = props.max
  num.value = newNum
  // 对外提供change事件
  emit('change', newNum)
}
</script>
<style scoped lang="less">
.xtx-numbox {
  display: flex;
  align-items: center;

  .label {
    width: 60px;
    color: #999;
    padding-left: 10px;
  }

  .numbox {
    width: 120px;
    height: 30px;
    border: 1px solid #e4e4e4;
    display: flex;

    >a {
      width: 29px;
      line-height: 28px;
      text-align: center;
      background: #f8f8f8;
      font-size: 16px;
      color: #666;

      &:first-of-type {
        border-right: 1px solid #e4e4e4;
      }

      &:last-of-type {
        border-left: 1px solid #e4e4e4;
      }
    }

    >input {
      width: 60px;
      padding: 0 5px;
      text-align: center;
      color: #666;
    }
  }
}
</style>